There is intense scientific interest in normal and pathological cognitive functioning in older adults that has been stimulated by the rapid increase in the older segment of the population. The increasing prevalence with advancing age of debilitating diseases like Alzheimer's disease has led to a need for clinical and research methods for measurement of effects of these diseases, and cognitive tests play a major role in diagnosis and monitoring of disease status and progression. Increasing demographic diversity creates special challenges for accurate measurement of cognition. Most neuropsychological tests of cognition that are in clinical and research use were developed using psychometric methods from the first half of the 20th century. There have been substantial advances in measurement theory and methodology, notably item response theory (IRT) and associated methods, that could have an important impact on the measurement of cognition, study design, and analysis of cognitive variables. This conference series is designed to promote the application of modern psychometric methods in research on cognitive decline associated with diseases of aging. Specific goals are: 1) to expose developing and established researchers in cognitive aging to modern psychometric techniques, 2) to expose experts in psychometric theory to the practical and theoretical concerns of cognitive aging research, and 3) encourage production of manuscripts based on the interactions of researchers, psychometricians, and statisticians during these conferences. We have had three successful annual conferences to date, and this experience has helped to shape our plans for the planned series of conferences. The format of the conferences will include didactic presentations by experts in cognitive aging and applied psychometric theory, demonstrations of psychometric and statistical analytic methods, and most importantly, hands-on experience using real data. This content and format is not only appropriate for encouraging education and collaboration of seasoned researchers but has also been an extremely effective learning environment for graduate students, postdoctoral fellows, and junior faculty with these interests. The main objectives of the first annual conference will be to address measurement issues that can enhance ability of cognitive tests to detect effects of Alzheimer and cerebrovascular disease. In subsequent years, the topics will focus on cognitive reserve, normative aging, the relationship between brain structure and cognition, and measurement bias in demographically diverse groups. As in previous years, there will be a heavy emphasis on workgroups organized around scientific analyses of real data, and we plan to disseminate the information resulting from these workshops in both traditional academic outlets (e.g. submission of manuscripts for peer reviewed scientific journals) and through symposia at annual scientific conferences. Dementing illnesses of aging like Alzheimer's disease are defined by their debilitating effects on cognitive abilities like memory, language, planning and organization, and reasoning. Modern psychometric methods have promise to improve measurement of cognition to enhance ability for early diagnosis and advance research on mechanisms and treatments of cognitive decline in older persons.